The results of the hematological indices were summarized in Table 1 while the serum biochemistry profiles were summarized in Table 2. Gross photographic illustrations of hoof with chronic laminitis is shown in Fig 1. Radiographic illustration of hooves with chronic laminitis are showed in Fig 2 and 3.
Table 1: Comparative mean value of haematological parameters of apparently healthy (group A) and horses with laminitis (group B).
Table 2: Comparative mean values of serum biochemistry profile of apparently healthy horses (group A) and horses with laminitis (group B)
Fig 1: Photographic picture of a hoof with laminitis showing serous fluid exudation (arrows) which are characteristics of laminae and dorsal coronary band compromise.
Fig 2: Lateromedial radiograph of hoof with laminitis as evidenced in the increased proximal-hoof phalanx distance (A) and distal-hoof phalanx distance (B).
Fig 3: Lateral radiograph of a hoof with laminitis as evidenced by the presence of with Founder Distance (FD) (increased coronary extensor distance (CED))
The mean values of PCV, HB and RBC were significantly lower (p < 0.05) compared to the apparently healthy horses (group A). Similar significant lower WBC counts in group B horses compared to the apparently healthy horses (group A) was recorded. The observed significant decrease in PCV, HB and RBC in chronic laminitis affected horses is similar to the findings of Sharma et al. (2015)
who reported a decrease in the PCV and RBC in chronic cattle laminitis. This significantly lowered PCV, HB and RBC depicts the anaemic state of the laminitis in horses. This decreased effects may be associated with the pathogenesis of laminitis which is often characterized with acute or chronic inflammation of the laminae (Sharma et al., 2015).
The most common cause of low RBC level in the circulation is chronic inflammation. Chronic inflammation is commonly related to conditions such as abdominal or hoof abscesses or laminar damage, cellulitis, pneumonia and peritonitis (Stockham and Scott, 2008)
. This happens because the body sequesters iron, which is necessary for red blood cell production, away from the infected area. The significant decrease in the PCV, HB and RBC in the horses with laminitis could also be due to infection condition, or immune mediated diseases. Nutritional factor (nutritional anaemia) could also have predisposed the horses to laminitis since lame horses may not be able to walk around and feed adequately. These findings are however not in agreement with those of Kameya (1973)
and Riber et al., (1995),
who reported non-significant differences in RBC values of healthy and acute laminitis affected horses. The differences in this study with report of Kameya (1973)
and Riber et al., (1995)
could stem from the fact that this study was carried out in chronic laminitis whereas their results were from acute induced laminitis. The discrepancies between this result and the previous findings could also be due to variation of etiology of the laminitis.
With regards to differential leucocytes (WBC) counts, a significant (p < 0.05) decrease in the mean values of neutrophil was found in the chronic laminitis horses (group B) than those found in the apparently healthy horses (group A). The observed neutropaenia could be a consequent of overwhelming bacterial infection or severe chronic inflammation which characterizes equine laminitis. This result is comparable to but slightly different from the findings of Riber et al., (1995)
who documented lower number of neutrophils in acute laminitis horses compared to the control. Severe inflammatory diseases, regardless of inciting agent, can lead to neutropenia if neutrophil margination into inflamed tissues exceeds the release of neutrophils from the bone marrow (Steven, 2000)
. With small storage pool of segmented neutrophils in the equine marrow, it is common for horses with overwhelming bacterial infection to have neutropenia (Steven, 2000)
. Lymphocytes, monocytes, basiophils and eosinophils remained statistically invariable (Table 2). The mean serum biochemical indices such as AST, ALT, ALP, total protein (TP), albumin, globulin and creatinine did not vary significantly (P > 0.05) between groups. Non-significant variation in the enzymatic activities of AST, ALT and ALP could suggest that there may not have the muscular, renal, intestinal and hepatic disorders associated with chronic laminitis in this study. However, Riber et al., (1995), Rashid, (1997)
, Hussain and Yousaf, (2004)
reported a significant increased enzymatic activity in the horses with acute laminitis. Total protein (TP), albumin, globulin and creatinine in horses with laminitis did not differ significantly (p < 0.05) with those found in the apparently healthy Nigerian horses (control). These results were comparable with the report of Ihedioha and Agina (2013)
in apparently health Nigerian horses and similar to the findings of Riber et al., (1995)
who also reported non-significant (p > 0.05) variation in the mean values of total plasma protein (TPP) between acute laminitis and non-affected Andalusian horses.